Bore-sight.



PATENTED OUT. 31, 1905.

No. 803,435. I G. N. SAEGMULLERJ BORE SIGHT.

' APPLICATION FILED OOT. 2251904.

[NVENTOR 4 m/yad 44 0 Milk? fi w g UN m UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Oct. 31, 1905.

Application filed October 22, 1904. Serial No. 229,611.

To all whom, it may concern.-

Be it known that LGnoReE N. SAEGMULLER, a Citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Bore-Sights, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a bore-sight, and particularly to a structure for ascertaining the accurate central axis of the bore of a gun or other piece of ordnance for the purpose of relatively adjusting a sighting-telescope to be used in connection therewith.

The invention has for an object to provide means for producing within the bore of a gun an image of an aperture or object disposed at the muzzle thereof together with a telescope disposed for adjustment in the field of said image.

A further object of the invention is to provide an improved means for maintaining and adjusting the bore-sighting telescope at the breech of the gun and for temporarily attaching the same thereto.

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features thereof defined by the appended claims.

In the drawings, Figure 1 is an elevation of a gun having the breech and muzzle thereof in section; Fig. 2, a central horizontal figure through the mounting for the bore-telescope in its holder; Fig. 3, an elevation of the apertured plate disposed at the muzzle of the bore; Fig. 4, a similar view of the cross-wires and holder disposed within the telescope; Fig. 5, a section on the line 5 5 of Fig. 2, and Fig. 6 a detail elevation of the holder for the bore-telescope.

Like ietters of reference refer to like parts in the several figures of the drawings.

The letter Adesignates a gun or other piece of ordnance which is provided at one end with the breech-opening A and the gas-chamber A disposed between the same and the bore thereof, while at the opposite muzzle portion A a closure or cap-plate B is disposed and provided with asmall aperture B, accurately disposed at the center of the axis of the bore. This plate may be supported in position in any desi red mannerfor instance, by the flange B engagin the face of the muzzle. The aperture B" in this plate permits the passage into the bore of a small ray of light from the muzzle end there which produces an image or halo of the aperture B intermediate of the muzzle and breech ends of the bore substantially at the position indicated bydotted lines at B and by a proper sighting and location of this image within a telescope G disposed at the breech the accurate center of the axis of the bore may be obtained. For the purpose of mounting this telescope so that it may be properly adjusted a holder 1) is provided which may be formed in any desired manner for instance, as shown in Fig. 6, with a series of spider arms D disposed at equidistant points and having extending inwardly therefrom adjusting-feet D each thereof being provided with a set-screw D to engage the inner face of the bore of the gun and having its head suitably graduated, so that the extent of movement thereof may be accurately determined. For the purpose of supporting this holder temporarily in position any desired means may be used; but as illustrating a preferable form thereof electromagnets D are disclosed as mounted upon these arms, the poles D thereof extending through the arms and contacting with the body of the gun, so that when the magnets are energized through the line D, which is connected in series therewith, the holder will be firmly retained in position by the magnetic attraction of the poles thereof.

The telescope G is disposed within a casing E, provided at its inner end E with a threaded portion adapted to engage the threaded hub of the holder D, and thus be rendered removable. The interior of the case E is provided with a convex socket-bearing E adapted to receive a convex ball member C, carried by the outer face of the telescope and accurately turned or formed to extend annularly around the same upon the longitudinal axis of the tube of the telescope. This convex or ball member C is retained in position by means of the usual adjusting-screw member E having a concaved face to complete the socketbearing, While the outer end of the casing E is provided with any desired number of setscrews E", adapted to contact with the tube of the telescope and hold it in its adjusted position. The telescope here disclosed may be of any desired character suitable for the use for instance, the ordinary terrestrial telescope provided with the usual eyepiece C extended beyond the casing E. Within the convex or ball portion C of the telescope is a transverse centrally-disposed holder F, provided with a series of finder-wires F, these wires being disposed so as to produce angular figures or parallelograms across the central opening 1! within the plate, and the wires may be secured by any desired meansfor instance, shellac, solder, or other attaching means placed over the free ends of the wires, as shown at F in Fig. Sr-while the plate F is held and adjusted in position by means of a series of screws Ffor instance, four, as shown in Fig.'5extending inward through recesses in the portion O and threaded th rough the flange F carried by the plate F. It will be seen that by these means the plate F may be accurately adjusted at the center of the tube of the telescope and there held in position. The terminal bands C and C and the ball member (3 are all turned or formed in the construction of the telescope C while the work is supported upon centers, and thus the ball member is exactly concentric with the geometrical axis of the telescope. Also the vertical sight-wires are located exactly at the cated by dotted lines in Fig. 1) into exactparallelism with the axis of the bore of the gun, so that when the gun is sighted from this telescope there is an accurate relation between the axis of the bore and that of the telescope, thus insuring a proper sighting.

In the application of the invention the apertured plate is first applied to the muzzle of the gun and the light, natural or artfieial, therethrough produces an aerial image of the opening B in front of the bore-telescope C. This image is not a real image of the opening B, because the bore-telescope is focused for a distant object, (the target,) but is a perfectly symmetrically enlarged image within the bore of said hole and in the air in front of said telescope, serving to enable the tilting of the bore-telescope by its adjustingscrews so that the cross hairs or wires shall biseet said image. The muzzle-plug is then removed, and the target is seen. The sighting-telescope is then turned upon the same distant object (target) and secured in position for regular use, it now being in exact parallelism with the bore of the gun. For the purpose of properly observing this image and locating upon it the finding-wires carried within the bore-sight telescope the latter is mounted by means of its holder within the breech of the gun, and the holder has the inward ly-extending feet which carry adjustingscrews bearing upon the inner face of the here. These screws are provided with graduatedheads, so that an exact adjustment may be determined for the purpose of centering the holder-that is, if in centering the holder a complete turn of one of the screws is required to contact with the bore this screw would be reversed for one-half of that distance and the remaining screw or screws adjusted to compensate and accurately center the holder, which when in position is temporarily and firmly retained by means of the electro or other magnets, the poles of which adhere to the end walls of the breech. The bore-telescope is mounted so as to be capable of a lateral ball-and-socket movement until it reaches an exact coincidence with the axis of the bore, when it is secured by the setserews carried by the casing. It may be found preferable to use more than single cross hairs or wires, as it would be easier and tend to greater accuracy to cut off equal segments than to simply quarter the image.

It will be obvious that changes may be made in the details of construction and configuration without departing from the spirit of the invention as defined by the appended claims.

Having described my invention and set forth its merits, what I claim, and desire to secure by Letters Patent, is-

1. In a bore-sighting apparatus, apertured means arranged approximately at the muzzle of a gun for producing an aerial image of said aperture within the bore adjacent to the breech.

2. In a bore-sighting apparatus apertured 'means for producing an aerial image of said aperture within the bore of the gun,and means for observing this image adjustably mounted in said bore at the axis thereof.

3. In a bore-sighting apparatus, a telescope located at the breech of a gun and apertured means at the gun-muzzle for producing an aerial image of the aperture within the gunbore and in advance of said telescope;

4:. In a bore-sighting.apparatus, a telescope located at the breech of a gun, means for producing an image within the gun-bore and in advance of said telescope, a holder 'for said telescope, and means carried by said holder for centering the same relative to the axis of the bore.

5. In a bore-sighting apparatus, a telescope located at the breech of a gun, means for producing an image'within the gun-bore and in advance of said telescope, a holder for said telescope, means carried by said holder for centering the same relative to the axis of the bore, and means for permitting a lateral adjustment of said telescope within said holder.

6. In a bore-sighting apparatus, atelescope located at the breech of a gun, means for producing an image within the gun-bore and in advance of said telescope, a holder for said telescope, means carried by said holder for centering the same relative to the axis of the bore, means for permitting a lateral adjustment of said telescope within said holder, and means for temporarily securing said holder within the breech of a gun.

7. In a bore-sighting telescope, a holder therefor, means for temporarily attaching said holder within the breech of the gun, and an apertured bore-closure removably mounted at the gun-muzzle and adapted to project an image of the aperture adjacent to the holder.

8. In combination with a bore-sighting telescope focused upon a distant object,of a holder, means for temporarily attaching it within the breech of a gun, and an apertured muzzleclosure adapted to project an image of its apertu re adjacent to the telescope.

9. In a bore-sight telescope, a holder provided with means for centrally supporting a telescope, and electromagnets carried by arms extended therefrom for temporarily attaching the holder within the breech o a gun.

10. In a bore-sighting apparatus, a muzzleclosure provided with an aperture at the axis of the gun-bore for producing an image within said bore, and means for observing said aerial image adjacent to the breech thereof.

11. In a bore-sighting apparatus, a muzzleclosu're provided with an aperture at the axis of the gun-bore for producing an image Within said bore, and means located in the breech of the gun for telescopically observing said image. I

12. In a bore-sight telescope, a holder constructed and arranged for attachment to the breech of a gun, a casing carried thereby having adj Listing-feet adapted to extend within the bore of a gun, and a telescope mounted Within said casing by a ball-and-socket connection for lateral movement therein.

13. In a bore-sight telescope, a holder constructed and arranged for attachment to the breech of a gun, a casing carried thereby having adjusting-feet adapted to extend within the bore of a gun, a telescope mountedwithin said casing by a ball-and-socket connection for lateral movement therein, and means car-' ried by the free end of said casing for retaining said telescope in adjusted position. I

14:. In a bore-sight telescope, a holder pro vided with horizontally-extending feet therefrom, and adjusting-screws carried by said feet to engage the inner face of a gun-bore.

15. In a bore-sight telescope, a holder provided with horizontally-extending feet therefrom, adjusting-screws carried by said feet to engage theinner face of a gun-bore, and magnets carried by the inner face of said holder to attract the body of the gun.

16. In a bore-sight telescope, a holder provided with horizontally-extending feet therefrom, adjusting-screws carried by said feet to engage the inner face of a gun-bore, magnets carried by the outer edge of said holder to attract the body of the gun, an interiorlythreaded hub to said holder, a casing threaded therein and having a socket-bearing adjacent to the hub, a telescope having aball portion set in said bearing, and a retaining-screw threaded .within said casingto engage said ball portion.

17. In a bore-sight telescope, a convex, circumferentially-extending portion upon its periphery intermediate of the ends thereof, a casing having a concave socket to receive said portion, andaplate provided with finder-wires to produce rectangular figures and disposed centrally within said convex portion and at a right angle to the optical axis of the telescope.

18. In a bore-sighting apparatus, the combination with means for producing an aerial image within the bore of a gun, a bore-telescope mounted in the line of the axis of the bore to sight said image, and a sighting-telescope secured to the gun and adjusted to receive the same image as that of the object sighted by the bore-telescope.

In testimony whereof I afiix my signature in presence of two witnesses.

GEO. N. SAEGR'IULLER.

Witnesses:

ALFRED T. GAGE, JOHN E. LANSDALE. 

